Abstract

Delayed photocurrents were observed in GaAs/AlAs type‐I short‐period superlattices by measuring time‐resolved photoresponses under ultrashort optical pulse excitation. According to the envelope function calculations, the X1 state in AlAs barriers resonates with the Γ2 state in the adjacent GaAs wells at a bias voltage where the delayed photocurrents were conspicuous. These results strongly suggest that the dynamic carrier transport process is significantly influenced by X1‐Γ2 resonance effects in the superlattices.